A 1978 landmark article highlighted the problem of drug errors (Cooper et al., “Preventable anesthesia mishaps: a human factors study,” Anesthesiology 49:399-406 (1978)). The investigators' found that mistaking syringes and ampules accounted for 14%, or the second most common cause, of preventable drug errors during anesthesia. This type of error was topped only by delivering incorrect gas to the patient, which occurred over 25% of the time. Follow-on studies as recent as 1985 continued to show that the most common cause of drug related error involved anesthetic gases. The concern highlighted by this study was that human error, such as unfamiliarity with machine operation and safety features, was the root of the problem in over 80% of these cases. Accumulating evidence from more recent studies show that errors involving the delivery of fresh gas accounted for far fewer errors of any type in anesthesia. Instead, these errors are now replaced by the delivery of intravenous medications. Intravenous medication errors occur with an incidence of between 0.11-0.75% with the most likely cause of error being mistaking drugs or syringes, overdose, or incorrect dosages. All told, 2% of all patients were injured as a result of errors and another 5.5% were exposed to near misses, where the correction of a mistake or good fortune, allowed the patient to escape unharmed.